SU597632A1 - Method of automatic control of process of preparing diluted sulfuric acid - Google Patents

Description

 ila FIG. 1 the scheme of adjustment of the preferred method has been passed; in fig. 2 is a plot of the flow rate of the incoming acid Egd condensate for a given monohydrate flow rate; Figs 3, 4 are graphs of pressure variation, cooTBeiCTByrofflHe current jjacxoay of the incoming acid (Fig. H) and the current consumption of water introduced by the incoming acid. The process proceeds in the following main technological devices: receiving tank 1, cooling tank 2, refrigerator section 3, intermediate tank 4, the monohydrate flow control circuit consists of flow sensors 5 and density. 6, converter 7, adder 8, to whose inputs signals of the current flow of incoming acid and constant reference 9, corresponding to the flow of mono-hydrate, are given to the multiplier unit 10 by a constant factor to match the flow rate and concentration, regulator C. Water flow control circuit the dilution includes a flow sensor 12, an adder 13, the output of which is the variable setting of the water regulator 14 for dilution, a concentration sensor 15 connected to the proportional regulator 16, the output of which is connected to one them from the adder 13 and inputs zakatchika 17. The circuit operates as follows: Target monohydrate flow set point adjuster 9 and zavodits in negative chamber of the adder 8 into a positive chamber which receives the output of the converter 7, the corresponding current value flowing yuschy acid consumption. Thus, at the output of the adder 8, a signal is generated corresponding to the difference between the current acid consumption and the monohydrate consumption (Fig. 2). The setting of the regulator 11 is the output signal of the density sensor b, which varies depending on the concentration, which allows changing the flow rate of the incoming acid so that, in terms of monohydrate, it is (assumed constant. To match the signal from sensor 6 and the output signal of the adder 8, the unit 1O is multiplied by a constant factor. Stabilization of the incoming sulfuric acid consumption With its concentration it allows you to construct a scheme for controlling the flow rate of water for dilution (with correction for the concentration of dilute acid). A warning signal for the main disturbance — the change in the acid consumption for dilution — is introduced into the circuit. The task for the water flow is calculated using the formula: (b. - monohydrate consumption; Cp diluted sulfuric acid concentration; GjS. & H. water consumption introduced with incoming sulfuric acid -QM & B. p. QB.p - water consumption for diluting a given monohydrate consumption to a given concentration, a constant value for a given mode; the signal corresponding to this difference is canceled & unit 17. In the graphs of FIG. 3.4 it can be seen, .VN is defined as Qc - Q LA, where Qc is the acid consumption. The signal corresponding to the flow rate of the injected VOD.Y is formed on the adder 8. Thus, formula ii) is implemented on the adder 13, the signal from the setpoint 17 enters the positive chamber, and the output of the adder 8 goes to the minus one. The output signal of the adder 13 is the setpoint of the water flow regulator for dilution 14. .. To more accurately maintain a given concentration and eliminate the concentration deviation due to the faults of the circuit devices, the output of the regulator 16, which changes the water setpoint, is inserted into the positive chamber of the adder 13. dilution so as to maintain the concentration at the desired value. Variable proportional regulator 16. is the output signal of the concentration sensor 15. The output signal of the regulator 16 is proportional to the deviation of the concentration from the set value, and the gain of the regulator is much smaller 1. Using the proposed method improves the control accuracy and, thereby, reduces the consumption of raw materials product unit while increasing the performance of the claims 1, a method for automatically controlling the preparation of dilute sulfuric acid by controlling the consumption of undiluted ki The slots of monohydrate consumption, water and diluted sulfuric acid concentration, characterized in that, in order to increase the accuracy of maintaining the stoichiometric ratio of diluted sulfuric acid to monohydrate consumption, a correction is made for the undiluted sulfuric acid consumption, the water content in undiluted sulfuric acid is determined injected into the regulation circuit of the consumption of unsaturated acid.

2. A method according to claim 1, characterized in that, in order to improve the quality of controlling the concentration of sulfuric acid, acid, the signal for water content in undiluted sulfuric acid is used to formulate a task for the flow rate of water supplied for dilution.

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